Methods of forming and using memory cell structures

Abstract

A method of filling vias for a PCRAM cell with a metal is described. A PCRAM intermediate structure including a substrate, a first conductor, and an insulator through which a via extends has a metallic material formed within the via and on a surface of the insulator. The metallic material may be deposited on the surface and within the via. A hard mask of a flowable oxide is deposited over the metallic material in the via to protect the metallic material in the via. A subsequent dry sputter etch removes the metallic material from the surface of the insulator and a portion of the hard mask. After complete removal of the hard mask, a glass material is recessed over the metallic material in the via. Then, a layer of a metal-containing material is formed over the glass material. Finally, a second conductor is formed on the surface of the insulator.

What is claimed as new and desired to be protected by Letters Patent of the United States is: 
     
       1. A method of forming a memory cell, the method, comprising:
 forming a first conductor over a substrate; 
 providing an insulator over the first conductor; 
 forming a via in the insulator to a surface of the first conductor; 
 forming a metallic material on a surface of the insulator and within and over a bottom of the via on an exposed surface of the first conductor; 
 depositing a protective barrier material over a portion of the metallic material at the bottom of the via and not over portions of the metallic material on the surface of the insulator; removing the metallic material from the surface of the insulator; 
 removing the protective barrier material from the via; and 
 forming additional material layers over the metallic material within the via to form a memory cell. 
 
     
     
       2. The method of  claim 1 , wherein the act of providing the protective barrier material is performed in a temperature range of 50° C. to 90° C. 
     
     
       3. The method of  claim 1 , wherein the act of depositing the protective barrier material comprises depositing silicon oxide. 
     
     
       4. The method of  claim 3 , wherein the act of depositing the silicon oxide comprises a chemical vapor deposition. 
     
     
       5. The method of  claim 1 , wherein the act of depositing the protective barrier material comprises depositing a spin-on material. 
     
     
       6. The method of  claim 1 , wherein the act of forming the metallic material comprises depositing a silver film. 
     
     
       7. The method of  claim 6 , wherein the act of depositing the silver film comprises a plasma vapor deposition. 
     
     
       8. The method of  claim 1 , wherein the act of removing the metallic material from the surface of the insulator comprises etching the metallic material from the surface of the insulator. 
     
     
       9. The method of  claim 1 , wherein the additional material layers comprise at least a glass material layer. 
     
     
       10. The method of  claim 9 , wherein the additional material layers further comprise at least a metal-containing material layer over the glass material layer. 
     
     
       11. The method of  claim 1 , wherein the step of removing the protective barrier material comprises providing a hydrogen fluoride solution on the protective barrier material. 
     
     
       12. A method for making a programmable conductor random access memory cell, comprising:
 forming a first conductor over a substrate; 
 forming an insulator over the substrate and the first conductor; 
 forming a via in the insulator extending to the first conductor; 
 forming a metallic material on a surface of the insulator and in the via in contact with the first conductor; 
 depositing a protective hard mask over a portion of the metallic material within the via and not over portions of the metallic material on a surface of the insulator; 
 removing the metallic material from the surface of the insulator; 
 removing the protective hard mask from the via; 
 forming a chalcogenide material in the via in electrical communication with the metallic material; 
 forming a metal-containing material in the via in electrical communication with the chalcogenide material; and 
 forming a second conductor on the surface of the insulator and in electrical communication with the metal-containing material. 
 
     
     
       13. The method of  claim 12 , wherein the act of forming the metallic material on the surface of the insulator and in the via comprises depositing the metallic material on the surface of the insulator and in the via. 
     
     
       14. The method of  claim 13 , wherein the act of depositing the metallic material comprises depositing a silver film. 
     
     
       15. The method of  claim 12 , wherein the act of depositing the protective hard mask comprises depositing silicon oxide. 
     
     
       16. The method of  claim 15 , wherein the act of depositing the silicon oxide comprises a chemical vapor deposition. 
     
     
       17. The method of  claim 12 , wherein the act of depositing the protective hard mask is performed in a temperature range of 50° C. to 90° C. 
     
     
       18. The method of  claim 12 , wherein the act of depositing the protective hard mask comprises depositing a spin-on material. 
     
     
       19. The method of  claim 12 , wherein the act of removing the metallic material from the surface of the insulator comprises etching the metallic material from the surface of the insulator. 
     
     
       20. The method of  claim 12 , wherein the act of forming the chalcogenide material in the via comprises depositing a chalcogenide glass in the via having a Ge x Se 100-x stoichiometry, wherein X is a positive integer. 
     
     
       21. The method of  claim 20 , wherein the Ge x Se 100-x  stoichiometry is in the range of Ge 20 Se 80  to about Ge 43 Se 57 .